Method of waterproofing joints



A ril 9, 1968 w. c. RENWICK METHOD OF WATERPROOFING JOINTS Filed Oct. 5. 1964 lg. 2a

F2921; I2 20 F zg. 2o

k m MW e we we m m w W H MMM HTTORIVEY United States Patent 3,377,226 METHOD OF WATERPROGFING JOINTS Wiliiam C. Renwiclr, Midland, Mich, assiguor to Dow Corning (Iorporation, Midland, Mich., a corporation of Michigan Filed Get. 5, 1964, Ser. No. 461,325 2 Claims. '(Cl. 156-250) ABSTRACT OF THE DISCLGSURE An improved method of waterproofing joints between substantially parallel surfaces spaced a suitable distance apart to allow for their contraction and expansion due to changes in their environment is disclosed. An elastic tube is cemented to the surfaces and then its outer Wall is slit. The inner wall of the tube remains intact and provides a seal which allows great expansion of the joint without impairing its watertight integrity.

The present invention relates to waterproofing of joints and has particular application in building construction, wherein it is desirable to waterproof a joint between two substantially parallel surfaces spaced apart by a distance which may vary due to thermal expansion and contraction or other reasons.

In building construction it is common practice to provide space between adjacent panels or sections to allow for thermal expansion and contraction and other changes in dimensions. If these joints are exposed to the weather the joints must be sealed if the building is to remain waterproof. Various types of sealing methods have in the past been used for this purpose. Among the methods suggested and used to some extent is the cementing of a flexible tube of rubber, plastic, or the like, in the joint. The tube becomes fiat as the joint narrows and is pulled into an elliptical configuration as the joint becomes wider. Such tubes, however, may be pulled only to the limit of the bond strength of the cement whereupon the cement fails, the tube snaps back to a substantially circular configuration and the joint is open. While the use of larger diameter tube might alleviate any difiiculty along these lines, it is more difficult to insert a larger diameter tube into a narrow joint and furthermore, larger diameter tubing is more expensive than small tubing.

An object of the present invention is the provision of a more economical sealing method for tubing sealed joints.

A further object is to provide a sealing method, wherein a relatively small diameter tube may be used to seal a relatively large j oint.

In accordance with these and other objects, the improved joint sealing method comprises sealing the joint by cementing a tube in the joint in a conventional manner and then slitting the outer wall of the tube. The single wall, which remains intact, provides a seal which is just as effective as a double wall for preventing water from entering the joint, but which allows much greater expansion of the joint without impairing its watertight integrity. While in effect, the joint is now a single strip cemented across the joint, the tubing is much easier to apply than a single strip would be.

The invention will be more easily understood by a consideration of the following detailed description when read in conjunction with the accompanying drawings wherein:

FIGS. 1a through 1d are cross-sectional views of a prior art tube sealed joint under dimensional change;

FIGS. 2a through 2d, are cross-sectional views similar to FIG. 1, but illustrating the improvement made possible by the present invention;

3,377,226 Patented Apr. 9, 1968 FIG. 3 is a view in perspective of a tool for use in slitting tubing in accordance with the present invention;

FIG. 4 is a view in perspective of the use of the tool of FIG. 3;

FIG. 5 .is a view in perspective of another method of slitting the tubing in the joint; and

FIG. 6 is a cross-sectional view through the tubing of FIG. 5.

Referring now to the drawings wherein like reference numerals designate like or corresponding parts throughout the several views there is shown in FIG. 1a a pair of building panels 11 and 12 having an open space 13 therebetween. The material of the panels forms no part of the present invention. The material may be masonry, steel, aluminum, or any other suitable building material. Held in the space 13 by cement bonds 14 and 15, to panels 11 and 12 respectively, is a length of tubing 16. In accordance with known techniques the tubing may be any of a number of elastic materials including, for example, natural rubber, synthetic rubbers, or organosilicones. The cement may also be any of a number of suitable commercially available compounds.

As shown in FIG. la, if the joint is relatively narrow, the tubing 16 takes an elliptical configuration being compressed between the panels 11 and 12. As the joint expands due to environment conditions, the tube passes through varying configurations, such as those seen in FIGS. 1b and 1c. However, due to the tensile strength of the tube and the stresses placed on it by the expanding joint, the joint may expand to the point where the forces exerted by the elasticity of the tube exceed the holding strength of the cement and the cement bond breaks allowing the tube to return to its initial circular configuration as shown in FIG. 1d. Obviously, at this point the joint is no longer Waterproof.

In accordance with the present invention, if the outer wall of the tubing is slit the effect of joint widening will be similar to that shown in FIGS. 2a through 2d. Assuming the same diameter tubing and the same elasticity and wall thickness as the tube in FIGS. la through 1d, the joint may expand a considerably greater distance without losing its watertight integrity. This is true because only a single wall of the tube acts to stress the cement bond between the tube material 16 and the panels, 11 and 12. Thus, the cost of larger tubing and the difficulty of inserting larger tubing into the joint are dispersed with thereby providing a more economical, but just as effective seal.

As shown in FIGS. 3 and 4, the tubing may be slit after being cemented in place by means of a simple hand tool 17 which preferably has a blunt extreme portion 18 which fits inside the tubing and a V-shaped knife edge 19 for slitting. The blunt extreme portion prevents damage to the inner wall of the tubing during the slitting operation and acts as a guide for the tool.

Another method of slitting the tubing is by positioning a steel cutting Wire 20 (FIGS. 5 and 6) within the tube and after cementing simply pulling the wire through the side of the tube.

Obviously, many different cutting methods and devices may be used without departing from the spirit and scope of the invention.

It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

That which is claimed is:

1. A method of sealing a joint between two variably spaced surfaces, which variance is caused by contraction and expansion of the surfaces due to changes in their environment, comprising in sequence:

first inserting a flexible elastic tube between, and in contact with, said two surfaces, then cementing one peripheral portion of said tube to one i of said surfaces along the entire length of said joint, and cementing another peripheral portion of said tube to said other surface along the entire length of said joint, and then slitting the wall of said tube in a direction substantially parallel to the axis of said tube.

2. A method of sealing a joint as described in claim 1, wherein said slitting of said tube is accomplished by positioning a cutting wire within said tube prior to insertion of said tube between said surfaces and pulling said cutting wire through the wall of said tube after said tube has been cemented to said surfaces.

References Cited UNITED STATES PATENTS 3,108,813 10/1963 Brown et a1. 277-4 FOREIGN PATENTS 1,145,850 3/1956 France.

DOUGLAS I. DRUMMOND, Primary Examiner. 

